BACKGROUND: Aspirin can decrease the incidence risk of high-risk crowdgroup of cerebral infarction, but there are still controversy if it might decrease the degree of disease in degree of patients with acute cerebral infarction.OBJECTIVE: To observe the effect of lower dose of aspirin during taking for a long time on disease degree of disease following onset of acute cerebral infarction.DESIGN: Grouping according to the admission time and 1:1 paired observation.SETTING: Department of Neurology, Qilu Hospital of Shandong University.PARTICIPANTS: The participants in present study were 321 patients with acute cerebral infarction who received treatments in the Department of Neurology, Qilu Hospital of Shandong University from January 1999 to June 2000. There were 190 male and 131 female ,with mean (65±11 )years of age. Inclusive criteria: ① A focal neurological disturbance occurred suddenly and had lasted for more than 24 hours, patients were admitted within 3 days after onset of disease; ② A computed tomography of the brain was performed and excluded hemorrhage in all patients; ③ The patients were proved intal carotid occlusions by clinical features and image findings; ④ The functions of limbs were normal (before the first stroke) or almost normal (before the second stroke). Exclusive criteria: ①The patients who had have cardiogenic cerebral embolism; ②The patients who had taken warfarin orally and other platelet agglutination drugs.METHODS: ①All the patients were divided into 2 groups according to whether they had taken aspirin before: aspirin-treated group (n=110) and blank control group (n=211). There were 70 male and 40 female in aspirin-treated group, with average(65±10) years of age.All patients had taken 50-100 mg/d aspirin for 6 months to 10 years before onset. There were 120 male and 91 female in blank control group, with average (65±13)years of age. Patients received a clinical scoring within 3 days and similar therapeutic measures (such as anti-platelet agglutination, improving cerebral circulation and metabolism-promoting reagent). Two groups of patients had the same basic conditions except for taking aspirin or not before. ②The matched pairs were made between 50 cases selected from aspirin-treated group and 50 cases from non-aspirin-treated groups according to age, gender, and other stroke risk factors. ③ Evaluation : Degree of disease after onset was evaluated by means of Acute Cerebral Infarction Clinical Neurologic Impairment Degree Scoring Standard of Carotid Artery System.MAIN OUTCOME MEASURES: Acute Cerebral Infarction Clinical Neurologic Impairment Degree Scoring Standard of Carotid Artery System.RESULTS: All 321 patients entered the stage of analysis with no loss in the midway. ① The symptom following onset of acute cerebral infarction was evaluated with clinical neurologic impairment scoring criteria, there were no significant differences between aspirin group and blank control group [(17.39 ± 9.90) vs (16.22 ±9.98) (t=1.025, P＞ 0.05)]. ② No significant differences were found in 1:1 matched pairs of 100 cases from aspirin group and blank control group (t=1.74, P＞ 0.05).CONCLUSION: Taking a lower dose of aspirin during long time may not decrease the degree of disease following onset of acute cerebral infarction.